This invention relates to the method or process for fabricating sandwich fiberglass laminates for boat hulls, components and the like.
Fiberglass components for marine vessels are normally made using an open mold by a molding technique known as "vacuum bagging." Unfortunately, vacuum bagging leaves bubbles which must be eliminated. Also, an open mold leaves only the outside layer of the component having a finished quality, thereby resulting in the inside layer having to be finished by hand, a time consuming and costly operation. Furthermore, hollow boxes for holding instruments, support beams, consoles and the like must be separately attached and added as the hollow boxes cannot be made part of the mold. Again, more time and costs are expended. Even furthermore, such fiberglass components made of several layers of laminate have a separation of layers at the edges, thereby requiring the edges to be sealed or covered after the molding process to avoid water intrusion and the separation of the layers at the edges.
Therefore, a great need exists for a molding process for making sandwich fiberglass components which solves the above problems.
The prior art includes numerous examples of molding processes, but none like the present invention. For instance, U.S. Pat. No. 4,504,341 issued to Radzwill, et al. on Mar. 12, 1985, teaches a method of shaping and laminating transparencies for use in aircraft and uses an atmospheric "bleed" hold in the process. An IBM Technical Disclosure, dated March, 1967, discloses a lamination method using a vacuum in a lower chamber with pressure applied from above. U.S. Pat. No. 5,108,532 issued to Thein, et al. on Apr. 28, 1992, teaches another method of forming plastic composite parts by drawing a vacuum on the bottom and applying pressure on top to shape an article. U.S. Pat. No. 4,816,106 issued to Turris, et al. on Mar. 28, 1989, discloses another method for molding plastic which uses an atmospheric "bleed" hole in the process. U.S. Pat. No. 3,861,977 issued to Wiley on Jan. 21, 1975, discloses a method of bonding a core layer between to shell layers. U.S. Pat. No. 5,131,834 issued to Potter on Jul. 21, 1992, discloses a vacuum bag molding method for consolidating composite parts. U.S. Pat. No. 3,775,214 issued to Winters on Nov. 27, 1973, discloses a method of fabricating hollow frames for boats which uses partial vacuum and atmospheric pressure. U.S. Pat. No. 5,427,518, issued to Morizot, et al. on Jun. 27, 1995, discloses another method of vacuum molding composites using an outside pressure source to keep a layer on a mold. Finally, U.S. Pat. No. 5,316,607 issued to Johnsen, et al. on May 31, 1994, teaches a method of making an ostomy device using a vented vacuum chamber.
Contrary to the afore-referenced prior art, the present invention allows for the manufacture of fiberglass components with a finish on both the outside and inside laminates. Furthermore, the present invention allows hollow boxes to be made part of the laminate by use of an atmospheric "feed" hole. The process disclosed in the present invention also involves the use of a vacuum manifold as part of the lay up which eliminates the edge separation of laminates typical of prior processes.